Conventional helicopters of the type pioneered by Igor Sikorsky are well known for their ability to take off and land more or less vertically, and to hover in a stationary spot. Helicopter type aircraft are proven, and of great utility through their ability to take off and land vertically. They have enabled saving of many lives and accomplished otherwise impossible tasks. However, the blades in an ordinary helicopter are vulnerable to foreign object damage when the machine comes too close to stationary objects, such as trees and the like. And the rotor and blade systems in the now-familiar types of helicopters tend to involve numerous moving parts, making them complex to fabricate and maintain. Thus, there have long been efforts to develop other types of vertical take off and landing aircraft.
One of the avenues that has been pursued has been to make circular or toroidal shaped aircraft with internal air moving systems. For instance, U.S. Pat. No. 2,927,746 to Mellen describes a disc shape aircraft with a central impeller that causes air to flow radially across the top of the aircraft and downwardly from the periphery. U.S. Pat. No. 2,718,364 of Crabtree describes another circular aircraft, where there is an internal propeller which forces air downwardly through an opening in the center of the machine. U.S. Pat. No. 2,997,254 to Mulgrave describes a disc shaped aircraft where an internal radial fan discharges air dowwardly from a nozzle around the periphery of the craft. Beck, Jr. in U.S. Pat. No. 5,170,963 describes a vertical take off and landing aircraft having a ducted fan which discharges air radially outward over airfoils placed around the periphery of the disc shaped craft. Flow over the airfoils also induces downward air flow, across the top surface of the craft, adding lift. U.S. Pat. No. 3,104,853 to Klein describes an embodiment of a vertical take off and landing machine, wherein a downwardly curved, open centrifugal impeller flows air downwardly. Vanes around the periphery of the craft counter the tendency of the cabin part of the aircraft to rotate in reaction to the impeller. The present invention represents a continuation of the evolution of concepts and ideas of the prior inventors.